Dual chamber processing systems are sometimes used to increase the efficiency of substrate processing by allowing two individual substrates to be processed simultaneously (i.e., one substrate in each process chamber of the dual chamber processing system). In some configurations, dual chamber processing systems may use shared resources, such as a gas distribution system to provide gases to the individual process chambers of the dual chamber processing system. However, when processing only one substrate in the dual chamber processing system, with one process chamber having no substrate to be processed, potential problems may arise in the empty process chamber relating to chamber conditioning, particle formation, and/or substrate defects.
Accordingly, the inventors have provided improved methods for processing substrates in a dual chamber processing system.